The relevant information is: Examples of this form of articulation are found in the hip, where the rounded head of the femur (ball) rests in the cup-like acetabulum (socket) of the pelvis, and in the glenohumeral joint of the shoulder, where the rounded head of the humerus (ball) rests in the cup-like glenoid fossa (socket) of the shoulder blade.
This justifies what answer for what question? Q & A: 
Passage: Examples of this form of articulation are found in the hip, where the rounded head of the femur (ball) rests in the cup-like acetabulum (socket) of the pelvis, and in the glenohumeral joint of the shoulder, where the rounded head of the humerus (ball) rests in the cup-like glenoid fossa (socket) of the shoulder blade. The shoulder includes a sternoclavicular articulation joint.

Question: Based on this passage, where are ball and socket joints found in the human body?
the hip , where the rounded head of the femur ( ball ) rests in the cup - like acetabulum ( socket ) of the pelvis , and in the glenohumeral joint of the shoulder , where the rounded head of the humerus ( ball ) rests in the cup - like glenoid fossa ( socket ) of the shoulder blade